Note: Depending on the carburetor version, 2 idle shut-off valves with different functions are installed.
The idle cut-off valve closes the fuel supply to the fuel jet when the ignition is turned on or when the highest speed of 6100±50 rpm is reached. The current supply is regulated by a delay relay. Until voltage is supplied, the valve is always open. After the ignition is turned off, the relay ensures that voltage is supplied for 6 to 16 seconds, as a result of which the valve closes the fuel supply during this time. Then the valve opens again by itself. In addition, the valve regulates the CO content. If the valve is defective, the engine runs for some time after the ignition is turned off. When the valve "hangs" in the closed state, the engine does not start. The idle cut-off valve is screwed under the carburetor in the float chamber.
The engine will not start
Remove the plug (1) from the idle speed shut-off valve (9).
Connect the test lamp to the plug and ground.
Turn on the starter. The lamp should not light. If the lamp lights when the ignition is on or while the starter is running, check the idle speed cut-off valve relay.
Note: After turning off the ignition, the lamp should light for 6-16 seconds.
Connect the test lead to the positive terminal of the battery and alternately connect and disconnect it from the shut-off valve contact. The valve should click, otherwise check the connection to the carburetor ground.
Note: If the valve clicks but the engine does not start, tap the valve hard and start the engine. Also, if the engine starts in this case, replace the valve as soon as possible.
The engine does not stop immediately after the ignition is turned off
Engine at operating temperature, oil temperature 65-75°C.
Start the engine and let it idle,
Remove the plug from the idle shut-off valve. Connect the valve plug contact with an auxiliary wire. The engine should stop, otherwise check the ground connection on the carburetor, if there is contact, replace the valve.